Аннотация:MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB210318.13 (trigger No 637729731,17h 16m 14.40s , -30d 17m 24.0s, R=9.71) errorbox 18422 sec after notice time and 65890 sec after trigger time at 2021-03-18 21:26:56 UT, with upper limit up to 14.9 mag. The observations began at zenith distance = 83 deg. The sun altitude is -52.2 deg. The galactic latitude b = 4 deg., longitude l = 356 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1571245 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________| _____________________|__________ ___________|_____________________ _______________|_____|_______|___ ____|________ 65920 | 2021-03-18 21:26:56 | MASTER- SAAO | (17h 36m 50.52s , -35d 54m 24.3s) | C | 60 | 14.1 | 66000 | 2021-03-18 21:28:16 | MASTER-SAAO | (17h 36m 56.20s , -35d 54m 15.6s) | C | 60 | 14.5 | 66080 | 2021-03-18 21:29:36 | MASTER- SAAO | (17h 36m 53.97s , -35d 52m 26.2s) | C | 60 | 14.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.